There’s a taxonomy now for levels of processing (NOVA groups); most research only finds problems with the highest level of processing (NOVA 4), which includes processing methods you can’t do in an ordinary kitchen, or that were not possible ~100 years ago (extrusion, moulding, preprocessing by frying are some examples given).
Do you happen to have any recommended pointers for research on health impacts of processed food? It’s pretty easy to turn up a few recent meta reviews, which seems like a decent place to start, but I’d be interested if there were any other sources, particularly influential individual experiments, etc. (It seems like there’s a whole lot of observational studies, but many fewer RCTs, for reasons that I guess are pretty understandable.) It seems like some important work here might never use the word “processing”.
UPP is terribly written and I imagine mostly useful for its bibliography (I skimmed it in an hour or so). Metabolical is better (although far too difficult a read to be a successful popsci book), although it isn’t specifically focused on processing techniques (it in particular discusses stripping out fibre, adding sugars, reducing water, as some major processing techniques with big issues). You might find something helpful looking in the refs section of either book.
Also as a brief pointer at another cool thing in Metabolical, Lustig claims that exercise is useful for weight loss mostly because of its beneficial impact on cell repair/metabolic system repair (something specific about mitochondria?) and not for the calorie deficit it may or may not create.
I consider Lustig’s science to be quite thorough, I like him a lot. The main point against him is that he personally doesn’t look very metabolically healthy, which I would expect of someone who had spent his life investigating and theorising about what influences metabolic health.
Thanks for the reference! I’m definitely confused about the inclusion of “pre-prepared (packaged) meat, fish and vegetables” on the last list, though. Does cooking meat or vegetables before freezing it (rather than after? I presume most people aren’t eating meat raw) actually change its processed status significantly?
I suspect the word ‘pre-prepared’ is doing a lot of the heavy lifting here—when I see that item on the list I think things like pre-fried chicken, frozen burger patties, veggie pakora, veggies in a sauce for a stir-fry, stuff like that (like you’d find in a ready-made frozen meal). Not like, frozen peas.
Yeah, it’d be helpful to know what heavy lifting is going on there, because I feel like there’s a pretty strong distinction between ‘frozen burger patties that are otherwise indistinguishable from unfrozen burger patties’ and ‘TV dinner’.
There’s a taxonomy now for levels of processing (NOVA groups); most research only finds problems with the highest level of processing (NOVA 4), which includes processing methods you can’t do in an ordinary kitchen, or that were not possible ~100 years ago (extrusion, moulding, preprocessing by frying are some examples given).
https://ecuphysicians.ecu.edu/wp-content/pv-uploads/sites/78/2021/07/NOVA-Classification-Reference-Sheet.pdf
Do you happen to have any recommended pointers for research on health impacts of processed food? It’s pretty easy to turn up a few recent meta reviews, which seems like a decent place to start, but I’d be interested if there were any other sources, particularly influential individual experiments, etc. (It seems like there’s a whole lot of observational studies, but many fewer RCTs, for reasons that I guess are pretty understandable.) It seems like some important work here might never use the word “processing”.
I don’t remember individual studies but two books that might be helpful:
Ultra-Processed People by Chris van Tulleken
Metabolical by Robert Lustig
UPP is terribly written and I imagine mostly useful for its bibliography (I skimmed it in an hour or so). Metabolical is better (although far too difficult a read to be a successful popsci book), although it isn’t specifically focused on processing techniques (it in particular discusses stripping out fibre, adding sugars, reducing water, as some major processing techniques with big issues). You might find something helpful looking in the refs section of either book.
Also as a brief pointer at another cool thing in Metabolical, Lustig claims that exercise is useful for weight loss mostly because of its beneficial impact on cell repair/metabolic system repair (something specific about mitochondria?) and not for the calorie deficit it may or may not create.
I consider Lustig’s science to be quite thorough, I like him a lot. The main point against him is that he personally doesn’t look very metabolically healthy, which I would expect of someone who had spent his life investigating and theorising about what influences metabolic health.
Thanks for the reference! I’m definitely confused about the inclusion of “pre-prepared (packaged) meat, fish and vegetables” on the last list, though. Does cooking meat or vegetables before freezing it (rather than after? I presume most people aren’t eating meat raw) actually change its processed status significantly?
I suspect the word ‘pre-prepared’ is doing a lot of the heavy lifting here—when I see that item on the list I think things like pre-fried chicken, frozen burger patties, veggie pakora, veggies in a sauce for a stir-fry, stuff like that (like you’d find in a ready-made frozen meal). Not like, frozen peas.
Yeah, it’d be helpful to know what heavy lifting is going on there, because I feel like there’s a pretty strong distinction between ‘frozen burger patties that are otherwise indistinguishable from unfrozen burger patties’ and ‘TV dinner’.